things that up until now the average flying public knew nothing about but of course any pilot at least on an aircraft like this would know. acars. think of it as an alternative way to communicate outside of the traditional radio systems. i can access it here if i look at this screen and pull it up. here i've got a simple menu. it's possible here to maneuver a mouse. a pilot could send a text message to the ground or the ground could send a text message to them. this is good when the aircraft is far out at sea and maybe radio communication can be spotty. another way to access the system, same acars, but this is a different backup unit, is to go in through this, what do i call this mitchell again? >> control display unit. >> control display unit. i hit this and you can see acars comes up. i punch this and i can get into the system this way. there's one here, one here, one here. that's three. with this there's four systems that are all part of acars. so four backups, if you will.